JPH04318313A - Adjusting method for spacing magnetic head gap - Google Patents

Abstract

PURPOSE:To adjust the gap space with high accuracy by irradiating a magnetic head base part between plural magnetic heads with a photo-thermo beam and adjusting the magnetic head gap in its position in deforming the magnetic heads. CONSTITUTION:In the case of two magnetic head chips 4 on one magnetic head base 1 like a combination magnetic head of VHS, when the gap space 7 is desired to be narrowed, the position of an irradiation point 2 is irradiated with a laser beam. On the contrary, when the gap space is desired to be widened, irradiation points 12 and 22 are irradiated with the laser beam. By this method, the magnetic head base 1 is distorted due to the photo-thermo beam, and the gap space can be adjusted with high accuracy without being influenced by a mechanical vibration and a temp. change.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD This invention relates to a method for adjusting the magnetic head gap distance in a magnetic storage device using a rotating cylinder.

0002

2. Description of the Related Art The positioning accuracy of a magnetic head used in a magnetic recording/reproducing device is an important accuracy that determines the format of information recorded on a medium.

[0003] For example, in a video tape recorder that is widely used for home use, the rotating cylinder has a 180°
Two pairs of magnetic heads mounted facing each other record and reproduce image and audio information while sequentially scanning the magnetic tape diagonally. The track pitch actually recorded on a magnetic tape is very narrow, 60 μm in the 2-hour mode and 20 μm in the 6-hour mode.

If the two pairs of magnetic heads described above cannot accurately scan these tracks, recorded information cannot be accurately reproduced, and the quality of the reproduced image will be significantly degraded. To prevent this, it is necessary to precisely match the scanning pitch of the magnetic head to the track pitch mentioned above, but one of the important factors that determines this scanning pitch is the number of magnetic head bases on one head base. If there is, then there is accuracy of the individual head gap spacing.

A combination magnetic head for VHS is shown in FIG. 2. The gap distance 7 between the standard 2-hour mode magnetic head and the triple 6-hour mode magnetic head on the left side of the magnetic head chip 4 is 740 μm. The method for fixing this gap interval 7 is (Fig. 3
). This device is a method in which the user is fixed while viewing a monitor 25 through an objective lens 24 so that the two head gaps 5 can be observed. First, fix the first head chip 4 to the combination head base, and after the resin hardens, fix the other head chip 14 by sandwiching it with a jig 40 so that the specified gap distance is 7. It is hardened with resin.

There is also a method of applying distortion to a plate by welding the plate (for example, Welding Engineering, author: Kunihiko Sato et al., published by Rikogakusha, 1979).

[0007]

[Problems to be Solved by the Invention] The conventional method of solidifying the resin while keeping the distance between two gaps at a constant value is
In the case of the combination magnetic head, the gap distance is as long as 740 μm, and in order to obtain a field of view in which both gaps can be observed, the magnification must be adjusted at 200 to 300 times using a monitor. The accuracy of this gap interval is not 10 μm or less. In this case one on one head base
With one head as a reference, the head on the head base 180 degrees opposite to this head is adjusted to a predetermined protrusion amount and fixed on the rotating cylinder. The other head chip on the same head base has a gap spacing of 740
If the two heads are adjusted exactly in μm, the other head will naturally be fixed to the cylinder with the heads facing each other 180 degrees with high accuracy.

However, at present, the head gap distance varies within a range of -10 .mu.m to +10 .mu.m from the standard value. Once the resin is solidified, it is impossible to adjust the gap distance after fixing unless the chip is removed.

Furthermore, when a pair of magnetic heads are arranged at 180 degrees, one magnetic head records one field on a recording medium such as a magnetic tape, and then the remaining magnetic heads of the pair record the next field. One field is recorded. When this is played back, the connections between the individual fields become precise and clear frames, resulting in high image quality. However, if the opposing heads are deviated from the 180-degree direction, the timing of the connections between the fields will be shifted accordingly, resulting in an awkward screen.

Furthermore, in a method of bending a plate material using a laser (for example, Japanese Patent Laid-Open No. 62-93028), the laser beam and the material to be processed are moved relative to each other along the bending line. In this case, there was a problem that the irradiation point gradually changed, making it difficult to make the amount of deformation uniform.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method that can solve the above problems and adjust the gap distance of a magnetic head with high precision without being affected by vibrations or temperature changes.

0012

[Means for Solving the Problems] In order to achieve this object, the present invention provides a method for adjusting the gap interval of a magnetic head disposed in a magnetic recording/reproducing device, which includes applying light and heat to the base portion of the magnetic head between each head chip. The head gap position is adjusted by irradiating the magnetic head and deforming the magnetic head. Further, it is also possible to adjust the magnetic head gap interval of a multi-magnetic head in which a plurality of magnetic head chips are provided on one magnetic head base. The magnetic head has a melted part that remains on the magnetic head base after being irradiated with light and heat. Also,
The direction of deformation of the magnetic head irradiated with light and heat is parallel to the sliding direction of the magnetic head chip.

[0013]

[Operation] The present invention uses laser processing, an example of which can deform the magnetic head, and deforms the magnetic head by irradiating the base portion of the magnetic head between the head chips of the magnetic head with laser light and heat. , adjust the magnetic head gap interval. The gap distance between the magnetic heads can be adjusted in units of 0.1 μm, and the magnetic head gap distance can be adjusted even when the magnetic head placed on a rotating cylinder is rotated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of magnetic head gap spacing adjustment according to the present invention will be described with reference to FIG. 1. For example, when there are two magnetic head chips 4 on one magnetic head base 1 such as a VHS combination magnetic head, adjust the gap distance 7 to the desired value while watching the monitor 25 using the conventional adjustment method. Get as close as possible. In the case of VHS, the gap spacing 7 is 740 μm. If the magnetic head chip 4 is hardened with resin on the magnetic head base 1, fine adjustment of the gap distance 7 cannot be performed in the conventional manner. Therefore, during this bonding, the target value of gap distance 7
If the magnetic head was misaligned, it would remain in use. However, the irradiation point 2 shown in (Figure 1)
irradiate to. After that, a part of the irradiation point 2 melts and becomes a melted part. The magnetic head is distorted due to light and heat, and the distance interval of the magnetic head gap interval 7 can be adjusted.

For example, if it is desired to narrow the gap interval 7 by 1 μm, a YAG laser beam is focused to a diameter of 600 μm at the position of the irradiation point 2 shown in FIG. 1, and the irradiation time is 10 μm.
When one pulse of ms is irradiated, the gap interval 7 of the magnetic head chip is shortened in the direction of narrowing, and it is possible to narrow the gap interval 7 by an amount equivalent to 1 μm.

[0016] Furthermore, when irradiation is performed with an irradiation energy higher than this, a deformation amount of 1 μm or more can be obtained. Since this amount of deformation is proportional to the irradiation energy, if one-tenth of the energy for deforming 1 μm is irradiated, a deformation amount of 0.1 μm is obtained, allowing fine adjustment. On the other hand, if you want to widen the gap interval, focus the YAG laser beam on the laser irradiation points 12 and 22 to a diameter of 600 μm and irradiate one pulse of 5 ms each, and the amount of deformation will be It is also possible to widen the head gap distance from 1 μm. Also, 100
If it is desired to adjust the magnetic head gap spacing by μm, the amount of deformation is proportional to the irradiation energy, so it is sufficient to apply 100 times the irradiation energy when adjusting the gap to 1 μm.

[0017] The deformation due to the strain caused by this laser is 3 degrees Celsius.
The deformation is not canceled even in an environment of 00 degrees. normal VT
Under the environment in which R is used, this amount of deformation will not be canceled, and once adjusted, it can be kept stable.

By automating the adjustment of the magnetic head gap interval, it becomes possible to incorporate it into a VTR mass production line, thereby improving its productivity. Furthermore, since the method for adjusting the magnetic head gap distance according to the present invention is not affected by mechanical vibrations or temperature changes, it is easy to realize a high-quality VTR.

Furthermore, this magnetic head gap interval adjustment method can be provided even when three or more magnetic head chips are installed on one magnetic head base, such as in a multi-head.

In this embodiment, welding deformation by laser beam irradiation using optical energy was used, but in principle any method that can perform local heating may be used. Examples include arc welding and electron beam welding using electrical energy, ultrasonic welding using ultrasonic energy, and gas welding using chemical energy.

The laser of this embodiment used short pulse oscillation of an Nd:YAG laser (wavelength: 1.06 μm). Further, when the pulse width of the excitation flash light was 1 msec and the excitation voltage was 450 volts, the laser energy obtained was about 1 joule per pulse.

[0022]

As described in the above embodiments, according to the present invention, the magnetic head is deformed by irradiating the magnetic head with light and heat in the method of adjusting the magnetic head gap interval. When there are multiple head chips on one head base, the gap interval can be adjusted in units of 0.1 micron. Additionally, automation allows for incorporation into a VTR mass production line, improving productivity. Furthermore,
According to the present invention, the head gap interval is not affected by mechanical vibrations or temperature changes, making it easy to realize a high-quality VTR.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a magnetic head used to adjust the gap distance of a magnetic head, explaining one embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional combination magnetic head.

FIG. 3 is an explanatory diagram of a conventional magnetic head gap interval adjustment method.

[Explanation of symbols]

1 Magnetic head base 2 Irradiation point (dissolved area after irradiation) 3. Magnetic head fixing screw hole 4 Magnetic head chip 5 Magnetic head gap 6 Glass part of magnetic head 7 Magnetic head gap spacing 12 Irradiation point (dissolved area after irradiation) 14 Magnetic head chip 22 Irradiation point (dissolved area after irradiation) 24 Objective lens 25 Monitor 40 Installation jig

Claims (4)

[Claims] 1. A method for adjusting a magnetic head gap interval, comprising: irradiating a magnetic head base portion between each magnetic head chip with light and heat to deform the magnetic head to adjust the position of the magnetic head gap. 2. The magnetic head gap spacing adjustment method according to claim 1, wherein the magnetic head gap spacing of a multi-magnetic head having a plurality of magnetic head chips on one magnetic head base is adjusted. 3. The magnetic head gap spacing adjustment method according to claim 1, further comprising a dissolving portion irradiated with light and heat on the magnetic head base. 4. The magnetic head gap spacing adjustment method according to claim 1, wherein the deformation direction of the magnetic head irradiated with light and heat is parallel to the sliding direction of the magnetic head chip.